Beamer, overlay and standalone

Question

Short version

Is it possible to use standalone to produce externally my figures with overlays and include them directly in my main document ?

More details

Using the answers of the question Beamer overlays, tikz external and custom file name and Integrating latexmk and TikZ external mode=list and make I have been able to outsource my Tikz pictures while using overlay.

More precisely, I have the following tex files

% tikz/fig.tex
\begin{tikzpicture}[transform canvas={scale=0.5}]
\node[visible on=<1->]  at (0,0) {Overlay 1};

\node[visible on=<2>]  at (2,0) {Overlay 2};


\end{tikzpicture}

% main.tex

\usepackage{tikz}
\usetikzlibrary{external}
\tikzexternalize[mode=list and make,prefix=tikz/]
\tikzset{
  invisible/.style={opacity=0},
  visible on/.style={alt={#1{}{invisible}}},
  alt/.code args={<#1>#2#3}{%
    \alt<#1>{\pgfkeysalso{#2}}{\pgfkeysalso{#3}} % \pgfkeysalso doesn't change the path
  },
}
\makeatletter
\newcommand*{\overlaynumber}{\number\beamer@slideinframe}
\tikzset{
  beamer externalizing/.style={%
    execute at end picture={%
      \tikzifexternalizing{%
        \ifbeamer@anotherslide
        \pgfexternalstorecommand{\string\global\string\beamer@anotherslidetrue}%
        \fi
      }{}%
    }%
  },
  external/optimize=false
}
\let\orig@tikzsetnextfilename=\tikzsetnextfilename
\renewcommand\tikzsetnextfilename[1]{\orig@tikzsetnextfilename{#1-\overlaynumber}}
\makeatother

\tikzset{every picture/.style={beamer externalizing}}

\begin{document}
\begin{frame}{Example}
    \begin{figure}
        \only<1>{\tikzsetnextfilename{fig}}
        \only<2>{\tikzsetnextfilename{fig}}
        \input{tikz/fig.tikz}
    \end{figure}
\end{frame}
\end{document}

Then, I can use latexmk with the following .latexmkrc

our %externalflag = ();
$lualatex = 'internal mylualatex %O %S %B';
sub mylualatex {
  print "Hello world\n";
  our %externalflag;
  my $n = scalar(@);
  my @args = @[0 .. $n - 2];
  my $base = $_[$n - 1];
system 'lualatex', @args;
  if ($? != 0) {
    return $?
  }
  if ( !defined $externalflag->{$base} ) {
    $externalflag->{$base} = 1;
    system ("$make -j8 -f $base.makefile");
  }
  return $?;
}

and it will produce all the figures (in my example two because I have two overlays) in parallel using make. The only issue now is that I would like to use standalone to be able to work directly on my picture and not recompiling the whole document each time.

I saw in the doc of standalone that it should be possible to generate frames with standaloneframe, but it is not really what I want since I want only pictures, and I did not succeed in including the resulting frame in my main document using \includestandalone anyway.